In folding doors comprising a plurality of door sections pivotally mounted with respect to one another about vertical axes, it is common to utilize a stationary upper pivot assembly mounted on an upper track which guides the sections and a bottom pivot assembly. It is desirable to provide in the bottom pivot assembly for both vertical and horizontal adjustment of the bottom pivot to accommodate the door opening. Many bottom pivot assemblies have been heretofore suggested for providing such vertical and horizontal adjustment.
For example, in U.S. Pat. No. 3,054,447, there is disclosed an arrangement wherein the bottom pivot comprises a pivot pin threaded into a sleeve in an opening in the bottom of the door that engages an opening in a bracket section that is, in turn, fastened but longitudinally adjustable by nut and bolt along a slot in a bottom bracket member. In order to adjust the door horizontally, the nut and bolt are loosened and the bracket section is moved. In order to adjust the door vertically, the pivot pin is rotated. However, there is nothing to prevent the rotation from occurring during the normal opening and closing of the doors so vertical adjustment can be lost. In U.S. Pat. No. 3,096,539, the pivot pin engages a member that is adjustable on the bottom pivot by rotation of a horizontal gear with a gear rack on the bottom pivot member. No provision is made for vertical adjustment. In U.S. Pat. No. 3,187,800, the pivot pin engages a socket in a pivot block that is, in turn, engaged with teeth on a bottom bracket. The vertical adjustment is achieved by threading or rotating the pivot pin. The horizontal adjustment is made by moving the pivot block to a new position along the track. A lock nut is utilized to the vertical adjustment position. In U.S. Pat. No. 3,233,657, the bottom pivot pin selectively engages one of the undulations of a member. However, in such an arrangement, the horizontal adjustment can be inadvertently changed by normal movement of the door.
In U.S. Pat. No. 3,328,832, the bottom pivot engages an opening in an intermediate member that is lifted to disengage teeth thereon from the bottom bracket to adjust the door horizontally. In U.S. Pat. No. 3,683,453, the bottom pivot has teeth thereon engaging corresponding teeth in a bolt for holding the vertical adjustment of the door. The bolt extends through an elongated opening in the bottom bracket and a nut is threaded on the bolt to lock the horizontal adjusted position. In such an arrangement, tools are required to make the horizontal adjustement. In U.S. Pat. No. 3,866,658, the bottom pivot pin engages an opening in a block that, in turn, has teeth thereon for engaging teeth on the bracket to provide horizontal adjustment. The pin is rotated to give vertical adjustment and a lock nut is used for locking the vertical adjusted position. In U.S. Pat. No. 4,106,158, the pivot pin has teeth thereon which engage complementary teeth on the bottom bracket. Vertical adjustment is achieved by rotating the pivot pin but there is no provision for locking the position of the pin. In the preferred form, the teeth are tapered downwardly and inwardly such that they can be disengaged in the normal operation of the door. In U.S. Pat. No. 4,109,346, the pivot pin engages a socket in a block that, in turn, has teeth thereon engaging teeth on the bottom bracket. Vertical adjustment is achieved by rotating a pivot pin and the pivot pin has a chisel point that engages the complementary socket for locking the pin in vertical adjusted position. The pivot block includes an integral spring that tends to urge the teeth of the block out of engagement with the teeth of the bracket and the teeth are shaped and positioned such that a longitudinal force on the door tends to disengage the teeth.
Among the objectives of the present invention are to provide a bottom pivot assembly which permits vertical and horizontal adjustment of the bottom pivot pin relative to the door without removing the door and wherein one adjustment will not affect the other; wherein the adjustment can be achieved without the use of tools; wherein the adjusted position, both vertically and horizontally, will be held and not affected by the normal operation of the door; and wherein the assembly can be manufactured at low cost.
In accordance with the invention, the bottom pivot assembly comprises a bracket adapted to be mounted beneath a section of the door. The bracket defines a track and a pivot block is guided along the track by the bracket. A sleeve is adapted to be mounted in a vertical opening in the lower end of a section of the door. The sleeve and the pivot pin have interengaging threads such that the pivot pin is vertically adjustable relative to the door. The block has a vertical opening therein and the pivot pin has the lower end thereof extending through the opening. The pin and the block have vertically engageable and disengageable teeth such that the teeth are engaged when the pin is moved relatively downward onto the block and said teeth are disengaged when said pin is moved relatively upward with respect to the block. The pivot block and the bracket have vertically engageable and disengageable teeth such that when the block is moved downwardly onto the bracket, said teeth are engaged, and when said block is moved upwardly relative to the bracket, the teeth are disengaged. Interengaging means between the pin and the block are operable upon lifting the door to lift the block and disengage the teeth of the block from the teeth of the bracket such that the teeth of the pivot pin are first disengaged from the teeth of the block permitting the pivot pin to be rotated to adjust the door vertically, and further lifting of the door will cause the interengaging means between the pin and the block to lift the block to disengage the teeth of the block from the teeth of the bracket permitting horizontal adjustable of the block relative to the bracket. Further lifting of the door disengages the pivot pin from the block when the pivot block contacts the bracket causing pressure to snap the pivot pin out of the opening in the pivot block.